A display device that displays information relating to fuel consumption in order to encourage a driver to drive with consideration for fuel consumption has been suggested. For example, Patent Literature 1 discloses a display device that displays instantaneous fuel consumption corresponding to the present fuel consumption and target fuel consumption corresponding to the fuel consumption which is a target, and also displays an accelerator depression amount with an indicator common to the instantaneous fuel consumption and target fuel consumption. With the display device disclosed in Patent Literature 1, the driver can visually and instantaneously determine the relationship between the change in instantaneous fuel consumption and the operation of depressing the accelerator. As a result, the driver is encouraged to drive so as to improve the instantaneous fuel consumption and can visually recognize the type of operations to be performed.
Examples of related art literature relevant to the present invention include Patent Literature 2 to 4. Patent Literature 2 discloses a display device that recalculates the amount of change of kinetic energy and the amount of change of potential energy of a vehicle into a distance that can be traveled and displays a substantial fuel consumption that also takes into account the recalculated travel distance. Patent Literature 3 discloses a display device that displays a revolution speed and a vehicle speed on the same screen. Patent Literature 4 discloses a display device such that when an accelerator depression amount display value corresponding to the actual accelerator depression amount and a target depression amount display value corresponding to the target accelerator depression amount are displayed, the target accelerator depression amount display value is fixed to a predetermined value at all times regardless of the target accelerator depression amount.